How to check if something is countable?

Question

I have a var: $a. I don\'t know what it is. I want to check if I can count it. Usually, with only array, I can do this:

if (is_array($a)) {
             


        

Answer 1

PHP 7.3

According to the documentation, You can use is_countable function:

if (is_countable($a)) {
    echo count($a);
}

Answer 2

For previous PHP versions, you can use this

if (is_array($foo) || $foo instanceof Countable) {
    return count($foo);
}

or you could also implement a sort of polyfill for that like this

if (!function_exists('is_countable')) {

    function is_countable($c) {
        return is_array($c) || $c instanceof Countable;
    }

}

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Note that this polyfill isn't something that I came up with, but rather pulled directly from the RFC for the new function proposal https://wiki.php.net/rfc/is-countable